Adapter for connecting card

ABSTRACT

The card adapter disclosed has the configuration that: all of the parts are mounted on a same surface of the circuit board in a foldable structure; the circuit board is folded until both boards face each other to insert into the card case; and the space just above the holder for a compact memory card is made up with the card case. This can realize a low profile connector for a compact memory card to provide a card adapter with CF type I compliant shape.

TECHNICAL FIELD

The present invention relates to a card adapter to connect a removablecompact memory card to portable information equipments represented by PC(personal computer), PDA (personal digital assistants), digital stillcamera or the like.

BACKGROUND ART

Recent notebook computers (personal computers) are generally providedwith PC card slots. The PC card inserted in the slot can extendfunctionalities of the notebook computers.

The PC card satisfies the PC Card Standard with a flat rectangular shapeof 54.0 mm wide, 85.6 mm long, and 3.3 mm (type I), 5.0 mm (type II) and10.5 mm (type III) high respectively. However, as even the PC card isnot compact enough to meet strong requirements for downsizing in recentportable information equipment represented by PDAs or digital stillcameras, a CF card that is more compact in size has been introduced inmany cases.

The CF card represented by the Flash memory card is used to store imagestaken by digital still cameras or schedule and address data in PDAs. TheCF card compliant with the CompactFlash Association Standard (hereafterreferred to as the first specification) has a flat rectangular shape of36.4 mm wide, 42.5 mm long, and 3.3 mm (type I) and 5.0 mm (type II)high respectively. Most recent PDAs and digital cameras adopt 3.3 mmhigh model (type I) being advantageous for product downsizing.

On the other hand, compact memory cards specialized in memory have beenused widely for digital still cameras, silicon-audio players or the likeas a storage media. These compact memory cards having memory IC chips orcontroller IC chips and directly packaged using resin have a feature ofextremely low profile. Smart media cards and MMCs (MultiMedia Cards)belong to this category. Moreover, the SD memory card (Secure Digitalmemory card) having copyright protection functions has become verypopular recently with its compact size, large capacity and high transferrate. Hereafter, standard for these compact memory cards is referred togenerically as the second specification.

The age of real multi-media has come and portable information equipmentsand notebook personal computers have become very popular due to theachievements of downsizing and high functionalities in portableinformation equipment.

In this situation, for instance, transferring images taken by digitalstill camera to notebook PCs to edit pictures on the PCs or exchangingdata between PDAs and notebook PCs are enjoyed everyday. Most notebookPCs are, however, not provided with slots to insert the compact memorycard directly while CF cards or other compact memory cards are wellestablished as storage media. To meet the requirements to connect the CFcards or compact memory cards to PC card slot formed according to the PCCard Standard, the PC card adapter has been provided so far.

Most modern PDAs or digital still cameras have been provided with slotsfor CF cards but have no slots to insert MMC or the SD cards directlythat have been used widely in recent years. Until now, any card adaptercompliant with 3.3 mm (type I) for PDAs or digital still cameras has notyet been developed.

The reason is that designing a card adapter thinner than CF type I isphysically impossible as the compact memory cards have a thicknessalmost similar to CF type I.

Information equipment having CF card slots compliant with theCompactFlash Association Standard have to satisfy a preconditionspecified in the standard: the compact memory card side must have asignal processing circuit to convert signals between the firstspecification and the second specification. Compact memory cards,therefore, without carrying the signal processing circuit cannot be useddirectly in the CF card slots.

Therefore, to connect the compact memory cards to information equipmenthaving the CF card slots, a CF-card-shaped card adapter provided with asignal processing circuit to convert data between both specifications isnecessary.

For instance, as disclosed in Japanese Patent Laid-Open Application No.2000-214970, conventional CF-card-shaped card adapter has slotconnectors mounted on the top surface of an internal circuit board toform a holder for a compact memory card. On the bottom surface of theinternal circuit board, the signal processing circuit is formed toconvert signals between both specifications. Therefore, the thickness ofthe card adapter can be the minimum when followings are stacked with nospace in between: a holder for a compact memory card or a slotconnector; a circuit board; parts for the signal processing circuit; andmetal covers to cover top and bottom surfaces of the card adapter.

Even in this case, to produce a card adapter thinner than CF type I isphysically impossible as compact memory cards have thickness near tothat specified for CF type I. Therefore, as disclosed for instance inJapanese Patent Laid-Open Application No. 2000-214970, a card adaptercompliant with CF type II has been realized (shaped 36.4 mm wide, 42.5mm long and 5.0 mm high as specified in CompactFlash AssociationStandard).

In another example, to allow a card adapter to connect to informationequipment having CF type I slot, a card adapter has been realizedcomplying the width and thickness of the card adapter with respect tothe insertion direction with CF type I and extending the longitudinallength along the insertion direction longer than CF type I.

Similarly, another CF type I “compatible” card adapter has been realizedthat holds a compact memory card in the holder with an end portionextending out of the card adapter.

As conventional compact memory cards have thicknesses approximatelyequal to the thickness specified for CF type I, commercializing a CFtype I card adapter has been physically difficult that must satisfyfollowing three requirements: (1) capable of connecting to informationequipment having a CF type I slot, (2) capable of including whole of theholder for a compact memory card and the signal processing circuit, (3)capable of holding a compact memory card without any extrusion out ofthe CF type I card adapter.

Japanese Patent Laid-Open Application No. 2000-214970 discloses aCompactFlash Association Standard type II compliant card adapter.Portable information equipment, however, represented by PDA or digitalstill camera has been in many cases provided with CF type I card slotdue to strong needs for downsizing. As the result, the present situationis that many portable information equipment with CF type I card slotcannot connect to type II card adapter.

Most portable information equipments are provided with a protection lidfor card slot inlet. Additionally, some of the equipments have afunction to detect closing of the lid and causing the equipment not tostart operation unless the lid is closed perfectly. Therefore, cardadapters with a longitudinal elongation along the card slot or cardadapters with an inserted compact memory card having an extrusion fromthe end of adapter even though the card adapter itself has the CF type Icompliant shape cannot be used for these equipment.

Most usual card adapters are made up to insert a compact memory cardfrom the rear end. Structures of card adapter with an inserted compactmemory card having an extrusion from the end have risks to drop off fromthe card adapter by unexpected external forces. In some card adapterssuch as disclosed in Japanese Patent Laid-Open Application No.2000-214970, the power supply control for compact memory cards,so-called “hot plugging”, is simplified as the aforementioned problemsis solved by modifying the adapter structure. However, detection ofinsertion and removal of a compact memory card in the card adapter hasbeen an essential function.

SUMMARY OF THE INVENTION

The present invention aims at solving the conventional problems with thefirst purpose of providing a CF type I card adapter that can includesall of the holder for a compact memory card and the signal processingcircuit, and can hold a compact memory card without any extrusion out ofthe CF type I card adapter.

The second purpose is to provide a card adapter with an improvedreliability by forming an adapter structure capable of preventing thecompact memory card from dropping off or from removing while the cardadapter is in the card slot, and a simple structure by simplifying thepower supply control for the compact memory card and by eliminating thedetection of insertion and removal of the compact memory card.

The card adapter of the present invention is to connect a compact memorycard compliant with the second specification to the CF card slotcompliant with the CompactFlash Association Standard or the firstspecification.

The card adapter includes a circuit board and a card case, and thecircuit board has:

-   -   a first connector compliant with the first specification;    -   a second connector compliant with the second specification; and    -   a signal processing circuit connected to the first connector and        the second connector to convert signals between the first        specification and the second specification, and    -   the card case accommodating and including the circuit board has:        -   a compact memory card inlet perpendicular to the insertion            direction of the card slot compliant with the first            specification,    -   wherein the card case and the second connector form the holder        for the compact memory card, and the card case makes up the top        portion of the holder for the compact memory card.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an outline of the card adapter used inthe preferred embodiment of the present invention.

FIG. 2 is a cross-sectional view of the card adapter along the line A-Ashown in FIG. 1.

FIG. 3 is an exploded perspective view of the card adapter shown in FIG.1.

FIG. 4 is a plan view of the circuit board used in the preferredembodiment of the present invention.

FIG. 5 is a side view of the circuit board used in the preferredembodiment of the present invention.

FIG. 6 is a plan view of the circuit board in a folded condition used inthe preferred embodiment of the present invention FIG. 7 is a side viewof the circuit board in a folded structure used in the preferredembodiment of the present invention FIG. 8 is a cross-sectional view ofthe circuit board along the line B-B shown in FIG. 7.

FIG. 9 is an expanded partial side view of the circuit board in a foldedstructure used in the preferred embodiment of the present invention

FIG. 10 is an exploded perspective view of the card adapter shown inFIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The card adapter of the present invention is described with reference todrawings. As shown in FIG. 1, card adapter 1 comprises first case 2,second case 3, CF slot connector 5, and card inlet 71. Card case 123 isan assembly of first case 2 and second case 3. SD card 100 has a writeprotect switch 101 on a side surface. An insertion direction of SD cardis indicated by arrow X, and an insertion direction of the card adapterto information equipment is indicated by arrow Y.

FIG. 2 shows a cross-sectional view taken along the line A-A of cardadapter 1 shown in FIG. 1. First case 2 is an integral mold of firstresin frame 21 and first metal cover 22. Second case 3 is an integralmold of second resin frame 31 and second metal cover 32. First resinframe 21 and second resin frame 31 are carried out ultrasonic welding.First metal cover 22 and second metal cover 32 can shield circuit board4 including signal processing circuit (not shown) from external electricnoises or static electricity and can protect noise radiations fromcircuit board 4.

Circuit board 4 is sandwiched between first case 2 and second case 3.First metal cover 22 and second metal cover 32 contact to circuit board4. Main board 41 is insulated electrically from first metal cover 22appressed to main board 41 by first insulation sheet 8 shown in FIG. 3.Similarly, sub-board 42 is insulated electrically from second metalcover 32 appressed to sub-board 42 by second insulation sheet 9.

FIG. 3 shows an exploded perspective view of card adapter 1 shown inFIG. 1. Circuit board 4 including signal processing circuit (not shown)comprises main board 41, sub-board 42 and flexible bend 43.Additionally, the card adapter includes: CF slot connector 5, SD cardconnector 6, circuit board first support (first support) 61, first uppersupport 611, circuit board second support (second support) 62, terminals63, first guide 65, second guide 66, third guide 67, card inlet 71,first insulation sheet 8, second insulation sheet 9, controller IC chip10 and write protect switch terminal 64 as shown in FIG. 4.

Here, SD card connector 6 makes up a housing including first support 61,first upper support 611, second support 62, first guide 65, second guide66 and third guide 67. SD card connector 6 includes first support 61 andsecond support 62. The adapter structure allows first contact portion 44of circuit board 4 to touch first support 61, and second contact portion45 of circuit board 4 to touch second support 62 when circuit board 4 isfolded to opposite faces. If first support 61 and second support 62 havea same height, and the step between first upper support 611 and firstsupport 61 is equal to the thickness of circuit board 4, the bottomsurface of circuit board 4 and first upper support 611 come to a samelevel when circuit board 4 is folded.

FIG. 4 is a plan view showing whole of the circuit board shown in FIG.3. The card adapter has a structure so as to form SD card holder 7 byfirst guide 65, second guide 66 and third guide 67 of SD card connector6 respectively. FIG. 5 is a side view of circuit board 4 shown in FIG. 4before folding, that is, before insertion into card case 123.

FIG. 10 shows another preferred embodiment of the card adapter in thepresent invention. After circuit board 4 is folded and inserted intocard case 123, circuit board 4 is fixed by insulating adhesives appliedinner face of card case 123, providing SD card connector 6 with nosupport for circuit board 4. For instance, first adhesive sheet 11 andsecond adhesive sheet 12 are both resin sheets having rubber adhesivessuch as polybuden or the like. The embodiment is to form the holder fora compact memory card on SD card connector 6 by first guide 65, secondguide 66, third guide 67 and first metal cover 22 as shown in FIG. 3.

In another aspect of the present invention, the insertion direction ofSD card (X) is at right angle to that of the adapter (Y) as shown inFIG. 1. The configuration can prevent SD card 100 inserted in cardadapter 1 from being removed while running. Therefore, a mechanism toswitch on/off power supply from SD card connector 6 to SD card 100 or amechanism to detect any compact memory card in the adapter can beeliminated as shown in FIG. 4.

Still another aspect is that main board 41 of circuit board 4 isgenerally L-shaped so as to prevent SD card holder 7 from being blockedwhen folded to the opposite face of sub-board 42 as shown in FIG. 5.

Still another aspect is described with reference to FIGS. 5 & 6. Whenmain board 41 is folded to the opposite face of sub-board 42, firstcontact portion 44 and second contact portion 45 of circuit board 4 areappressed to first support 61 and to second support 62 respectivelyenabling distance (Z) between the facing circuit boards to keep aprescribed dimension.

Still another aspect is described again with reference to FIGS. 5 & 6.When main board 41 is folded to the opposite face of sub-board 42, firstadhesive sheet 11 and second adhesive sheet 12 provided on first metalcover 22 and on second metal cover 32 respectively, resinous sheetsapplied with rubber-based adhesives such as polybuden or the like asshown in FIG. 10 can keep distance (Z) between the facing circuit boardsin a prescribed dimension.

Still another aspect is a configuration in that signal processingcircuit such as controller IC chip is not installed in circuit board 4.That is, CF slot connector 5 is connected to SD card connector 6electrically, and that circuit to convert pin arrangement is installedin circuit board 4.

Preferred Embodiment 1

The card adapter of the present invention is described in detail furtherwith reference to preferred embodiment 1.

Card adapter 1 is an assembly of first case 2 and second case 3 bondedtogether by ultrasonic welding to form card case 123 as shown in FIG. 1.First case 2 is an integral mold of first resin frame 21 and first metalcover 22. Second case 3 is also an integral mold of second resin frame31 and second metal cover 32. Then, first resin frame 21 and secondresin frame 31 are ultrasonically welded to complete card case 123.

Circuit board 4 including signal processing circuit (not shown) as amain part, is folded and held in card case 123 composed of first case 2and second case 3 bonded together.

CF slot connector 5, which is a first connector compliant with the firstspecification, is disposed on the front edge facing CF type I slot, andSD card inlet 71 to insert SD card 100 is disposed on one side of theadapter. That is, the insertion direction (X) of SD card 100 for cardadapter 1 is at right angle to the insertion direction (Y) of adapter 1.

In this embodiment, the top of SD card connector 6, which is a secondconnector compliant with the second specification, contacts first metalcover 22. Therefore, SD card connector 6 and first metal cover 22 holdSD card 100 inserted in SD card holder 7. The configuration can provideSD card connector 6 with the minimum thickness as no press mechanism isneeded to SD card 100 from above SD card connector 6.

To shield circuit board 4 from external electric noise or staticelectricity and to protect noise radiations from circuit board 4, firstcase 2 and second case 3 have integral molded first metal cover 22 andsecond metal cover 32 respectively.

Circuit board 4, held between first case 2 and second case 3, isappressed to first metal cover 22 and second metal cover 32. Firstinsulation sheet 8 insulates main board 41 from first metal cover 22appressed to main board 41 electrically. Second insulation sheet 9insulates sub-board 42 from second metal cover 32 appressed to sub-board42 electrically.

SD card connector 6 surface-mounted on circuit board 4, the main part ofcard adapter 1, is disposed at the back of SD card holder 7. SD card 100inserted from inlet 71 is coupled to card adapter 1 mechanically as wellas electrically.

SD card 100 is a sheet-type card embedding a resin packaged IC (notshown) with a plurality of terminals disposed on the bottom surface.

Card adapter 1 has circuit board 4 internally, and circuit board 4includes main board 41, sub-board 42 and flexible bend 43 to connectmain board 41 and sub-board 42.

Main board 41 includes mainly controller IC chip and its peripheralcircuits (not shown), and is formed generally L-shaped in plan view.

Sub-board 42 carries mainly CF slot connector 5, SD card connector 6 andits peripheral circuits (not shown).

Flexible bend 43 includes a wiring conductor (not shown) to connectcircuits between main board 41 and sub-board 42.

Circuit board 4 includes: CF slot connector 5 compliant with the firstspecification; SD card connector 6 compliant with the secondspecification; and signal processing circuit mainly involving controllerIC chip 10 and its peripheral circuits (not shown).

A signal processing circuit (not shown) is disposed in the card adapterso as to use a compact memory card compliant with the secondspecification in an equipment provided with a card slot compliant withthe first specification. This is because the signal processing circuitis necessary in any one of followings: equipment with a card slot; acompact memory card compliant with the second specification; and a cardadapter to insert a compact memory card.

The signal processing circuit (not shown) receives, via pattern wiringof circuit board 4, signal compliant with the first specification to andfrom CF slot connector 5 and signal compliant with the secondspecification to and from SD card connector 6. Then the signalprocessing circuit (not shown) converts data between bothspecifications.

SD card connector 6 mounted on sub-board 42 includes: terminals 63corresponding to the terminals (not shown) disposed on the bottomsurface of SD card 100; and write protect switch terminal 64corresponding to write protect switch 101 disposed on a side surface ofSD card 100. Terminals 63 and 64 are made of a resilient conductivematerial

First support 61 and second support 62 are disposed on the top surfaceof external periphery of SD card connector 6. The configuration can holdfirst contact portion 44 and second contact portion 45 of main board 41when circuit board 4 is folded, and can keep distance (Z) between mainboard 41 and sub-board 42 facing each other in a prescribed dimension.

SD card connector 6 has first guide 65, second guide 66 and third guide67 internally to limit front and right and left sides positions ofinserted SD card.

As the insertion direction (X) of SD card is at right angle to theinsertion direction (Y) of the card adapter, SD card 100 can be insertedto or extracted from card adapter 1 only when card adapter 1 is out ofthe card slot. As a result, the ability of insertion/removal of SD card100 with card adapter 1 being coupled (in a running state) to equipment(not shown), so-called hot plugging, needs not be assured. Therefore,terminals to switch on/off the power supply from SD card connector 6 toSD card 100 or to detect any SD card 100 remaining in the adapter arenot necessary any more.

Both first support 61 and second support 62 disposed on the top surfaceof external periphery of SD card connector 6 form a step equal to thethickness of the circuit board and can provide distance (Z) between mainboard 41 and sub-board 42 folded to face each other in a prescribeddimension.

At the time, what is important is that parts mounted on main board 41and facing parts mounted on sub-board 42 must be disposed so as not tocollide with each other. That is, a 3 dimensional designing is requiredto dispose parts such that the sum of heights of facing parts does notexceed the distance (Z) between two facing boards when circuit board 4is folded.

Structure of circuit board 4, folded at flexible bend 43 until mainboard 41 faces sub-board 42, and inserted into card adapter 1 are shownin FIGS. 6 to 8. As main board 41 is formed generally L-shaped, even ifmain board 41 is folded to the opposite face of sub-board 42, the top ofSD card connector 6 is open. That is, main board 41 has an open areaequal to or wider than SD card holder 7 at the place facing SD cardholder 7. In preferred embodiment 1, main board 41 is formed L-shaped toform an open area. However, the form is not limited to L-shape but forinstance main board formed U-shaped for forming the open space may bealso acceptable. As main board 41 does not cover SD card connector 6,the thickness of card adapter 1 can be the height stacking: first metalcover 22; SD card connector 6; sub-board 42; second insulation sheet 9;and second metal cover 32. That is, as the thickness of main board 41 isnot added to the total height, card adapter 1 can be thinneraccordingly.

Though circuit board 4 includes main board 41, sub-board 42 and flexiblebend 43 in preferred embodiment 1, integrating main board 41 andsub-board 42 can eliminate flexible bend 43.

Preferred Embodiment 2

Next, preferred embodiment 2 that provides distance between main board41 and sub-board 42 of folded circuit board 4 with a prescribeddimension is described

FIG. 10 shows the card adapter used in preferred embodiment 2 of thepresent invention. Instead of first support 61 and second support 62used for SD card connector 6 in preferred embodiment 1, insulatingadhesive is employed. Adhesive sheet 11, for instance, is applied onfirst metal cover 22 appressed to main board 41, and adhesive sheet 12is applied on second metal cover 32 appressed to sub-board 42. Theconfiguration can hold the facing distance (Z) between boards of thefolded circuit board in a prescribed dimension. Adhesive sheet is aresinous sheet applied with rubber-based adhesives such as polybuden orthe like. The configuration can eliminate first insulation sheet 8 andsecond insulation sheet 9 used in preferred embodiment 1.

Needless to say, the adhesive fixing is not limited to rubber adhesivessuch as polybuden or the like.

Additionally, needless to say, even a kind of circuit board 4, having nosignal processing circuit (not shown), that connects CF slot connector 5to SD card connector 6 electrically by pattern wirings to convert pinarrangements without carrying any signal conversion can be adopted inpreferred embodiment 2 of the present invention.

Next, the operation of card adapter of the present invention isdescribed.

Card adapter 1 having an outline identical to CF type I compliant withthe CompactFlash Association Standard (the first specification) has SDcard holder 7 to insert SD card 100 compliant with SD Card AssociationStandard (the second specification) internally. As SD card 100 isinserted in SD card holder 7 without any extrusion, card adapter 1 withinserted SD card 100 can become a CF type I card. By introducing cardadapter 1 of the present invention, therefore, PDAs or digital stillcameras with CF type I slot can use SD card 100.

Card adapter 1 has the structure with: CF slot connector 5 disposed onfront edge surface of card adapter 1 facing CF type I card slot; and SDcard inlet 71 formed on a side surface of card adapter 1. That is,insertion direction (X) of SD card 100 with respect to card adapter 1 isat right angle to insertion direction (Y) of card adapter 1 with respectto CF type I card slot. This can prevent SD card 100 inserted in cardadapter 1 from being removed while running. Consequently, there is noneed to take into account the so-called “hot plugging”, and detection ofinsertion and removal of SD card 100 in the adapter may be eliminated.Therefore, the configuration enables to design card adapter 1 easilywith a simplified structure of SD card connector 6 and to improve theproduct reliability.

Although the embodiments are explained when the invention is applied toSD card, the invention is also applied to Multi Media Card.

INDUSTRIAL APPLICABILITY

As described above, the present invention can realize a card adapterhaving a signal processing circuit to convert signals between the firstspecification and the second specification with a card thicknesscompliant with CF type I, as a low profile connector for a compactmemory card can be provided.

Additionally, the structure of second supports can be downsized andsimplified as mechanisms to detect any compact memory card compliantwith the second specification staying in the adapter can be eliminated.This can provide a cheaper second supports. At the same time, partsconsisting of the signal processing circuit can be arranged easily forthe card adapter, CF type I compliant shape, having the signalprocessing circuit to convert signals between the first specificationand second specifications.

Additionally, the thickness limit of circuit board of the card adapter,CF type I compliant shaped, having the signal processing circuit iswidened, as an area of upper board of circuit boards that is foldedcorresponding to the compact card holder is removed. This makes itunnecessary to use a thin circuit board.

Additionally, the distance between the main board and sub board of thecircuit board folded to opposite faces and inserted into a card case iskept by circuit board supports. This can prevent parts facing each otherfrom being damaged by collision and can make it unnecessary to disposeother materials for electrical insulation.

Additionally, resin sheets applied with rubber adhesives such aspolybuden or the like to keep the distance between the main and subboards of the circuit board folded can prevent parts facing each otherfrom being damaged by collision. This makes it unnecessary to disposeinsulation sheets for the electrical insulation.

Additionally, the present invention can provide the card adapter with CFtype I compliant thickness for a type of card adapter that performs pinarrangements between the first specification and second specifications.

1. A card adapter used to couple a compact memory card compliant with asecond specification to a CF card slot compliant with a CompactFlashAssociation Standard or a first specification, the card adaptercomprising a circuit board and a card case, the circuit board including:a first connector compliant with the first specification; a secondconnector compliant with the second specification; and a signalprocessing circuit connected to the first connector and the secondconnector to convert signals between the first specification and thesecond specification; and the card case accommodating the circuit boardand including: an inlet for the compact memory card at right angle to aninsertion direction of the card slot compliant with the firstspecification, wherein a holder for the compact memory card is formed ofa housing of the second connector and the card case, and the card caseis used as a top portion of the holder and the circuit board is used asa bottom portion of the holder.
 2. The card adapter of claim 1, whereinthe circuit board mounts the first connector, the second connector andthe signal processing circuit in a same surface, and has a foldablestructure.
 3. The card adapter of claim 1, wherein the circuit boardcomprises a main board, a sub-board and a flexible bend to connect themain board and the sub-board, and is folded at the flexible bend toinsert into the card holder, and the main board and the sub-board faceseach other in the card case.
 4. The card adapter of claim 3, wherein thesub-board mounts the first connector and the second connector in a samesurface, the main board mounts the signal processing circuit in the samesurface, and the first connector and the second connector are connectedvia the signal processing circuit.
 5. The card adapter of claim 3,wherein at least one of the main board and the sub-board in a foldedstructure has an opening equal to or wider than the holder in a portioncorresponding to the holder.
 6. The card adapter of claim 3, wherein themain board is L-shaped and is positioned on the second connector housingwhen the main board is folded.
 7. The card adapter of claim 3, whereinthe holder is formed between one surface of the card case and thesub-board.
 8. The card adapter of claim 3, wherein the holder is formedby one surface of the card case, the sub-board and the housing of thesecond connector.
 9. The card adapter of claim 3, wherein housing of thesecond connector holds a distance between the main board and thesub-board facing each other.
 10. the card adapter of claim 1, whereinthe circuit board connects the first connector and the second connectorelectrically, and mounts a circuit to convert a pin arrangement.
 11. Acard adapter used to couple a compact memory card compliant with asecond specification to a CF card slot compliant with a CompactFlashAssociation Standard or a first specification comprising a circuit boardand a card case, the circuit board including: a first connectorcompliant with the first specification; a second connector compliantwith the second specification; and a signal processing circuit connectedto the first connector and the second connector to convert betweensignals compliant with the first specification and signals compliantwith the second specification; and the card case accommodating thecircuit board and including: an inlet for the compact memory card atright angle to an insertion direction of the card slot compliant withthe first specification; and a holder for the compact memory cardinserted from the inlet, wherein the circuit board mounts the signalprocessing circuit, the first connector and the second connector on onesurface, and has a structure enable to fold until both of the circuitboards face each other, and wherein the surface mounted with the signalprocessing circuit is appressed to a circuit board support provided on ahousing of the second connector to keep a distance between both of thefolded circuit boards in a prescribed dimension.
 12. The card adapter ofclaim 11, wherein the circuit board connects the first connector and thesecond connector electrically, and mounts a circuit to convert a pinarrangement.
 13. A card adapter used to couple a compact memory cardcompliant with a second specification to a CF card slot compliant with aCompactFlash Association Standard or a first specification comprising acircuit board and a card case, the circuit board comprising: a firstconnector compliant with the first specification; a second connectorcompliant with the second specification; and a signal processing circuitconnected to the first connector and the second connector to convertbetween signals compliant with the first specification and signalscompliant with the second specification; and the card case accommodatingand including the circuit board comprising: an inlet for the compactmemory card at right angle to an insertion direction of the card slotcompliant with the first specification; and a holder for the compactmemory card inserted from the inlet; wherein the circuit board mountsthe signal processing circuit, the first connector and the secondconnector on one surface, and has a structure enable to fold until bothof the circuit boards face each other, and wherein the circuit board ina folded structure where the both circuit boards face each other isbonded to the card case using an insulating adhesives to keep a distancebetween both of the folded circuit boards in a prescribed dimension. 14.The card adapter of claim 13, wherein the card case has a top surfaceand a bottom surface, and the main board is bonded inside of the topsurface via an insulating adhesive layer and the sub-board is bondedinside of the bottom surface via the adhesive layer.
 15. The cardadapter of claim 13, wherein the circuit board connects the firstconnector and the second connector electrically, and mounts a circuit toconvert a pin arrangement.